Certain fishing rods have for a number of years been made of fiber glass filaments in a tapered shape and adapted to bend into a parabolic contour in response to the pull of a fish. In order to reduce weight and increase flexibility, a tubular rod is ordinarily preferred, and U.S. Pat. No. 2,749,643 discloses a rod having an outer layer of longitudinally extending glass fibers and an inner layer of close helically wound glass fibers, all of the fibers being bonded together by a suitable flexible plastic resin. The outer fibers are said to serve as tension and compression members yieldingly to resist bending of the rod and the inner fibers provide hoop strength to maintain a circular cross section and resist crushing, and thus maintain uniform radial spacing of the outer fibers from the neutral axis to obtain maximum bending resistance in those fibers. As far as we are aware, such rods have been lacking in resistance to transverse crushing loads, such as occur when the rod is inadvertently stepped on or is closed in a car door, and often prematurely fail when sharply bent.
More recently, tapered hollow rods have been produced having an inner layer of helically wound graphite filaments and an outer layer of longitudinally extending graphite filaments. However, due to the fact that the graphite filaments have a modulus of elasticity approximately three times that of glass fibers, it is difficult to obtain requisite flexibility and proper bending contour under load, which is attempted by cutting of or graduating the outer longitudinal filaments and thus simultaneously gradually reducing the thickness of the outer layer in the direction of the smaller end of the rod. This construction provides a rod that is considerably lighter than all glass tubular rods previously discussed and with comparable, but not markedly increased, strength.